From 1931780a2051db6fe228df3ba4b7f30baf42fd0f Mon Sep 17 00:00:00 2001
From: Michael Tremer <michael.tremer@ipfire.org>
Date: Thu, 4 May 2023 16:41:47 +0000
Subject: [PATCH] pakfire: Fetch more user/group information at startup

Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>
---
 src/libpakfire/pakfire.c | 81 ++++++++++++++++++++++++++++++++++------
 1 file changed, 69 insertions(+), 12 deletions(-)

diff --git a/src/libpakfire/pakfire.c b/src/libpakfire/pakfire.c
index 765f075b3..bb2831ab2 100644
--- a/src/libpakfire/pakfire.c
+++ b/src/libpakfire/pakfire.c
@@ -22,6 +22,7 @@
 #include <errno.h>
 #include <fts.h>
 #include <linux/limits.h>
+#include <pwd.h>
 #include <stddef.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -81,8 +82,16 @@ struct pakfire {
 	FILE* lock;
 
 	// UID/GID of running user
-	uid_t uid;
-	gid_t gid;
+	struct pakfire_user {
+		uid_t uid;
+		char name[NAME_MAX];
+		char home[PATH_MAX];
+	} user;
+
+	struct pakfire_group {
+		gid_t gid;
+		char name[NAME_MAX];
+	} group;
 
 	// Mapped UID/GID
 	struct pakfire_subid subuid;
@@ -168,11 +177,11 @@ int pakfire_on_root(struct pakfire* pakfire) {
 }
 
 uid_t pakfire_uid(struct pakfire* pakfire) {
-	return pakfire->uid;
+	return pakfire->user.uid;
 }
 
 gid_t pakfire_gid(struct pakfire* pakfire) {
-	return pakfire->gid;
+	return pakfire->group.gid;
 }
 
 const struct pakfire_subid* pakfire_subuid(struct pakfire* pakfire) {
@@ -416,7 +425,7 @@ static int pakfire_safety_checks(struct pakfire* pakfire) {
 		return 0;
 
 	// We must be root in order to operate in /
-	if (pakfire->uid) {
+	if (pakfire->user.uid) {
 		ERROR(pakfire, "Must be running as root on /\n");
 		errno = EPERM;
 		return 1;
@@ -728,7 +737,7 @@ static int pakfire_set_cache_path(struct pakfire* pakfire) {
 	// Fetch the path from the configuration file
 	const char* path = pakfire_config_get(pakfire->config, "general", "cache_path", NULL);
 	if (!path) {
-		const char* home = pakfire_get_home(pakfire, pakfire->uid);
+		const char* home = pakfire_get_home(pakfire, pakfire->user.uid);
 		if (!home)
 			return 1;
 
@@ -746,6 +755,53 @@ static int pakfire_set_cache_path(struct pakfire* pakfire) {
 		path, pakfire->distro.id, pakfire->distro.version_id, pakfire->arch);
 }
 
+static int pakfire_setup_user(struct pakfire* pakfire) {
+	struct passwd user;
+	struct passwd* u = NULL;
+	struct group group;
+	struct group* g = NULL;
+	char buffer[1024];
+	int r;
+
+	// Fetch the UID/GID we are running as
+	const uid_t uid = geteuid();
+	const gid_t gid = getegid();
+
+	// Fetch all user information
+	r = getpwuid_r(uid, &user, buffer, sizeof(buffer), &u);
+	if (r)
+		goto ERROR;
+
+	// Store UID
+	pakfire->user.uid = uid;
+
+	// Store username
+	r = pakfire_string_set(pakfire->user.name, user.pw_name);
+	if (r)
+		goto ERROR;
+
+	// Store home directory
+	r = pakfire_string_set(pakfire->user.home, user.pw_dir);
+	if (r)
+		goto ERROR;
+
+	// Fetch all group information
+	r = getgrgid_r(gid, &group, buffer, sizeof(buffer), &g);
+	if (r)
+		goto ERROR;
+
+	// Store GID
+	pakfire->group.gid = gid;
+
+	// Store name
+	r = pakfire_string_set(pakfire->group.name, group.gr_name);
+	if (r)
+		goto ERROR;
+
+ERROR:
+	return r;
+}
+
 PAKFIRE_EXPORT int pakfire_create(struct pakfire** pakfire, const char* path,
 		const char* arch, const char* conf, int flags,
 		int loglevel, pakfire_log_callback log_callback, void* log_data) {
@@ -779,10 +835,6 @@ PAKFIRE_EXPORT int pakfire_create(struct pakfire** pakfire, const char* path,
 	p->nrefs = 1;
 	p->flags = flags;
 
-	// Store the UID/GID we are running as
-	p->uid = geteuid();
-	p->gid = getegid();
-
 	// Set architecture
 	pakfire_string_set(p->arch, arch);
 
@@ -801,6 +853,11 @@ PAKFIRE_EXPORT int pakfire_create(struct pakfire** pakfire, const char* path,
 			pakfire_log_set_priority(p, log_priority(env));
 	}
 
+	// Setup user/group
+	r = pakfire_setup_user(p);
+	if (r)
+		goto ERROR;
+
 	// Initialise configuration
 	r = pakfire_config_create(&p->config);
 	if (r)
@@ -838,14 +895,14 @@ PAKFIRE_EXPORT int pakfire_create(struct pakfire** pakfire, const char* path,
 	// Fetch sub UID/GIDs
 	if (!pakfire_on_root(p)) {
 		// UID
-		r = pakfire_getsubid(p, "/etc/subuid", p->uid, &p->subuid);
+		r = pakfire_getsubid(p, "/etc/subuid", p->user.uid, &p->subuid);
 		if (r) {
 			ERROR(p, "Could not fetch subuid: %m\n");
 			goto ERROR;
 		}
 
 		// GID
-		r = pakfire_getsubid(p, "/etc/subgid", p->uid, &p->subgid);
+		r = pakfire_getsubid(p, "/etc/subgid", p->user.uid, &p->subgid);
 		if (r) {
 			ERROR(p, "Could not fetch subgid: %m\n");
 			goto ERROR;
-- 
2.39.5